Apparatus for cutting helical bevel teeth



H. H. TALBOT APPARATUS FOR CUTTING HELICAL BEVET TEETH Feb. 9 1926. I 1,572,624

Filed Sept. 1, 1921 8 Sheets-Sheet l JNVE'NTOR.

1,572,624 H. H. TALBIOT APPARATUS FOR CUTTING HEL ICAL BEVEL TEETH Filed Sept. 1. 19-21 8 Sheets-Sheet 2 Feb. 9 1926.

H. H. TALBOT APPARATUS FOR CUTTING HELICAL BEVEL TEETH Filed Sept. 1, 1921 8 Sheets-Sheet 5 JNVEA'TOR Feb. 9 1926. 1,572,624

H. H. TALBOT I APPARATUS FOR CUTTING HELICAL BEVEL TEETH I Filed Sepi 1. 1921 8 Sheets-Sheet 4 JN VE'N T012.

Feb. 9,1926. 1,572,624

H. H TALBOT APPARATUS FOR CUTTING HELICAL BEVEL TEETH Filed Sept. 1, 1921 e Sheets-Sheet 5 s 7 JNWVENTOR. A W 70 M Feb. 9 1926. 1,572,624

H. H. TALBOT APPARATUS FOR CUTTING HELIGAL BEVEL TEETH Filed Sept. 1, 1921 B Sheets-Sheet a .INVEN 0R Life/@404 Feb. 9 1926.

H. H. TALBOT Filed Sept. '1, 1921 Feb. 9 1926. 1,572,624

H. H. TALBOT APPARATUS FO RCPTTING HELICAL BEVEL TEETH Filed Se t. 1, 1921 8 Sheets-Sheet 8 v JNVENTOR.

Patented Feb. 9,

burrs stars eraur rricn;

E-IO'WARD H. TALBOT, OF W0O$TER, OHIO, ASSIGNOR 01E GNE-I-EAI.-F TO LOUIS A. VJ'OOIDARD, 0F WOOSTER, CHI

APPARATUS FOR CUTTING HELICAL IBEVEL TEETH.

Agplication filed September To all whom it may con 0cm Be it known that I, Hownnn H. Tanner, a citizen of the United States, residing at l vooster, in thecounty of Wayne and State of Ohio, have invented certain new and useful Improvements in Apparatus for Cutting Helical Bevel Teeth, of which the following is a specification.

My invention refers to the art of cutting gear teeth, and more particularly the cutting of helical teeth, either single or double, in bevel gears. Such forms of teeth bear a relation to the ordinary straight teeth of bevel gears similar to that which the helical teeth of cylindrical gears bear to the straight teeth of ordinary spur gears. The cutting of helical teeth is accomplished by the use of a rotating end milling cutter, the axis off which is approximately normal to the elements of the pitch cone or" thegear, which cutter travels in a rectilinear path preterably towards the cone center of the gear. In order to etlect the diagonal or helical cut across the face of the blank, the gear blank is rotated in synchronism with such travel or feed, whereby to effect a resulting" curved, diagonal or helical tooth across the gear face.

In cutting; single helical teeth. the rotation of the blank is continuous, and for double helical teeth, the direction of: rotation ot the blank is reversed when the cutter is about midwa across the face of the b n t l rebv producing a reversed curve or helical cut, with a resulting \l-shaped or helical tooth,

By reversing the rotation of the blank at two or more points across its face, the term of the teeth may be correspondingly varied to the number of the altenating tooth sections, hereinafter described.

lVhile nretcrrcd practice involves the use of a preliminary or roughing cutout first, and then a finishing cut to produce the final form of the finished tooth, it will be understood that in certain cases the finished tooth face may be made in a singl cut. The invention involves means for ace rately posi tiouingg and supporting the blank and for intermittently shitting and rotating" it with relation to the cutter, means for mounting and driving the cutter, an indeiiing mechanism providing for correct cutting; of successive teeth around the face of the blank to "face plate on the 1, 1921. Serial No. 497,493.

ensure proper spacing, and various other features of operation and mechanism, as shall be more fully hereinafter set forth.

One preferred embodiment ota machine adapted to carry out the invention shown in the accompanying drawings, in which:

Fig. l is a general plan View of the com plete apparatus as atsembled;

2 is an enlarged plan view, partly in section, showing the operative mechanism of the cutter and gear blank adjusting drive mechanism Figs. 3 and i are detail plan views o1 the clutch shifting and lover controlling mechanism for effecting change in the directionot rotation of the gear blank;

5 is a sectional detailview of one of the lever controlling disks, taken on the line VV of Fig. 4C;

Fig. 6 is a sectional detail view in plan of the gear blank actuating and indexing mechanism;

Figs. 7, 8 and 9 are diagrammatic views showing the operation of the cutter with relation to the blank at successively advancing positions; a

Fig. 10 is a detailplan view, partly in section, of the cutter mechanism in operative relation to the gear blank and its supporti i and rotating mechanism;

showing the drive transmission for the cutter mechan sm, the section being indicated the line XlV-XlV of Fig. (3;

B itz. 15 1s a transverse sectional view 0 the line E'rI XV of F 1g. 10;

showing the clamping mechanism for the line XVI XVI of 1%;

l? 17 is a detail view in elevation showing; the change speed. gearing for the cutter and gear blank adjusting drive mechanism.

In, general, the machine comprises, in addition to its main supporting frame, three Fig. 11 is a transverse sectional viciv I. 16 is a detail vertical sectional view.

main operating units suitably connected and synchronized so as to cooperate in performing the several necessary functions. These are, a gear spindle and face plate support and its parts, generally indicated by the letter'A; a cutter and gear blank adjusting drive mechanism, generally indicated by the letter B; and a cutter mechanism C. These are 'mounted in operative relationship as shown in the somewhat diagrammatic representation of Fig. 1, and I will now describe these several unitary' or main elements and their parts in detail.

Referring to the unit A, a is the gear blank of a bevel gear upon which the heli cal teeth are to be cut in the manner indicated in Fig. 10; The blank is mounted by its hub on the expanding sleeve 2 of a tapered arbor 3 of spindle ii: and tightened thereon by nut 5 on the threaded end of the arbor. The cone center of blank a, i. e., the radial pitch center of the teeth, is capable of adjustment with relation :to the pivoted center 0 of the annularly swinging frame of the cutter mechanism C, towards or from the pivotal center, on' the axial center line w, to, of the gear blank and its supporting spindle. This provides for ofsetting the cone center *5 more or less to ensure the desired tapering depth of teeth by action of the milling cutter c in its radial iovement across and through the face of the blank on the radial line 0, c, and in parallelism with the feed screw of the cutter mechanism C, as hereinafter described. The inner end of arbor 3 ispreferably jour nalled in a supporting bearing 6 of the main frame 7, towards the cone center t. A face plate 8 is also provided, securely bolted to the spindle and arbor, andmay be used'for chuck attachment of the gear blank when requiredby its size. -Otherwise, the

blank may be merely mounted and secured on the end of the arbor, as shown. I

Spindle 4' is journalled or housed in a rotatably adjustable cylindrical sleeve 9, which in turn rests in bearings 10 extending upwardly from the main frame '4'. A depending worm wheel quadrant 1 1 is bolted or otherwise secured to the inner end of sleeve 9 and a worm index wheel 12 is secured to the other end of spindle 4:. The quadrant is for the purpose of securely clamping the face plate 8, when the face plate is used, to prevent any slippage or relative movement between thetwo, about the axis to, w, of the spindle. A further purpose of the quadrant is to fixedly connect with and effect intermittent forward and back rotation of the blank during radial travel of the cutter, for the formation of the helical teeth, as hereinafter described. The function of the index wheell12 and its associated change gear mechanism is to impart the desired periodical amount of rotation to may be used for large diameter gears.

movement backwardl of base the blank to properly index or divide it, for each cutting operation and the desired number of teeth.

Quadrant 11, secured to sleeve 9, is provided at its upper portion with bolting extension 13 for a triangular shaped bracket 1%. capable of fixed connection with the face plate and blank spindle, to hold the blank in fixed relation to the quadrant. Bracket l -i is provided with means for'clamping and unclamping the blank so that it may be relatively shifted as successive series of teeth are cut around its face.

The bracket is provided with upper and lower holes 15 16, either of which may be used, depending on the size of the face plate, for extension therethrough of a bushing 17 through which extends a clamping bolt 18.- Said bolt has a head 19 engaging the annular T slot 20 of face plate 8 and its shank extends throughbushing 17. The threaded end of bolt 18 engages the hub of. a quadrant nut 21 having an intervening bearing collar and adjusting set screws 22 therefor. The nut 21 is actuated by a toothed gear segment 23 engagedby double toothed rack 2 L slidably mounted in bearing on bracket 14, and having a fluid actuated piston 26 in cylinder 27, also mounted on the bracket] The cylinder is provided, with suitable valve controlled supply and exhaust connections whereby, upon application of pressure on the piston rod side of pistonv 26, nut21 will screw up on bolt 18, thereby binding and securing the face plate, and locking it against relative rotational movement. In like manner, application of pressure on the opposite side of the piston will release the face plate for rotat-ive movement, the bolt head 19 sliding in the annular slot 20.

-Face plate 8 is so constructed that an auxiliary face plate ring 8 of increased diameter may be attached around it. with an annular slot 20 coinciding with the center of outer bolt hole 15, as indicated in dotted lines, Fig. 14. Such extended face plate In such case, bolt 18, with a lefthand thread. and bushing 17 are mounted in hole'l5, and a co acting quadrant nut and its toothed segment are utilized, engaging the upper series of teeth of rack 2 as indicated in dotted lines. Spindle bearing support 7 is slidably mounted on housing base 28 capable of adj ustment with the gear blank towards and from the 'pivotal center 4), on center line 10, w, and of being secured in position by bolts 29, for proper setting of the gear blank. Such construction also provides for ample 7 to admit of removal of the cut gear, placing of anotherblank. or other operations. The seg ment 11 and the supported blank (1 are actuated by worm 30 of shaft 31 mounted at one end in thrust bearing 32 and at the other in bracket hearing 33. Said bearing has a l'iousing 3ft surrounding driven bevel gear 35 of shaft 31 and driving bevel gear 36 of spline shaft 37, the latter being in sliding driving engagement with the terminal 38 of the cutter and gear blank adjusting drive unit 13. i

G our 38 has an extended hub 39 proper y hey-seated for engaging spline shaft 3. and journalled in bearing 4:0 of the frame of unit Gear 38 being thus fixed against lateral movement, shaft 37 may slide through it incidental to the movement of lieau e' support '7 and shaft 37 will he in driving engagement with the gear at all positions. Gear 38 is driven by pinion 4.1 of shaft 42 of gear h x I), and shaft 4-?) is driven by change gear and intermediateidler change gears 4%. 415 from gear' ifi of shaft 145?. Gears 4% and 4l5are adj ustably inounted by stud 48 in the slot of a supporting arin 4-9 pivot-ed to the gear box 7) at 50, {111C provided with an arc slot 51 and a securing stud and nut 52. (See Fig. 17.) By this means. the arm is adjustable for the pur pose of nerinitting the use of various sets gears as may be required.

Shaft is provided with loose gears 53, 5%, each having a clutch for connection with a sliding clutch splined on the shafts-.7 and adapted to operativelyconnect with one or the other, or to assume a neutral position. See Sheet 2.) Gear 53 is geared through idler gear 56 with pinion and gear o l is geared directly with pin1on58, both of which pinions are secured to drive shaft 59 which is coupled directly to the drive shaft 60 of motor 61 with intervening clutch 180. Thus, with constant rotational direction of shaft 59, shaft 4L7 will be driven in the same direction when clutch 55 engages gear and in the opposite direction when I the clutch enga 'es gear 5- Also, starting with shaft 60, it will be seen that power is transmitted in two distinct transmissions, one tl'lrough shaft 59 and its connections to the feed of the table cutt r mechanism C, the other through shaft 37 and its coni'iections as described, for actuating th rotation of the gear blank.

The end inilling cutter c is mounted in n chuck ($2 on the end of rotating horizontal splined spindle 68, driven through gearing (i4, 65, shaft 66, and suitable reducing gearing from motor 67. The spindle and its chuck and housing are slidably adjustable in supporting ways 68 arranged across a lower supporting table or frame 69, which is itself movable in a transverse horizontal plane, to carry the spindle and its cutter towards and from the work. Adjustment of the spindle housing and its shaft is by screw Tl) mounted in table (59 engaging threaded Eng 71 and having a hand wheel 72 (l 12), so that the cutter may be withdrawn axially from its cutting position, when desired.

Table (39 slidably mounted on the supporting pedestal or bed i3, which in turn is mounted "for radial adjustment around the vertical center line i), o, (Fig. ll) corresponding to center 4; 10). lit will be noted also that the pivoting center o, v, en'- tends tl'irough the horizontz-il center line n), to, of the spindle and its arbor. At its d, the bed 73 is supported by annu- .lar on ion "Z-S on the annular faee 74- of supporting base forming the main sup port for the cutter niechanisin. The edge a, Mi- H. ."i1

(1L annu in support roomy ,e suite.) j in taste setting of the bed to thedesirc-d angle, with relation to the taper of the blank to be pedestal T6 on annular tracl-:' .vay 7? concentric with center 4), to which it may be sepinion '28 engages annular rack 79 by whi h the bed may be swung around to the do Lion.

The table 69 and the cutter are shifted to a threaded shaft SGengaging a worm nut 81 located between embracing depending ru gs anchored its other end by a thrust hearing 83 in a housing 8% extending from bed locked in position for feeding the table by rotation of threaded shaft 80 through nut mounted in bearings 87 on the table, and provided with a hand wheel 88 and lock nut 85 may be used to rotate worni nut 81 to 2 tion ary.

Shaft St) is criren thro ,g h worn mounted in bearings 93, ill, of bed The bed is pivotaily connected to 75 on the shu .ed through 96, 97, with 1 shaft coin ides with such the bed. Motion is transmitted to shaft 96 from drive shaft 59 tl'irough bevels 99, 100,

By this means, the cutter table is actuated at any position by feed screw through the 61. By the mechanism just described, it will be seen that the cutter supporting for work with relation to the particular gear blank to he cut, and that the rotating scribed with an indicating scale to facilicut. At its outer portion, bed 73 rests by cured by bolts, as shown. A hand actuated sired position, and there locked for operaf wards and from the pivotal center by means h aring s, of the table and the shaft 73 at its inner end. Worm nut 81 may be 81, held stationary by worin of shaft 88 89. By loosening the lock nut 89,)the worm djust the table on the threaded shaft, when so in housing 8-3: and worm .11. of shift 92 pivotin 'center liner, n, by a nod 95, and

center, nrov for pivotal swinging of shaft 101, and bevels 102,108 respectively.

intermediate gearing directly from motor mechanism may be accurately set to position cutter 0 will be fed in a radial. path across the bevel face of the gear, The gear crank itself, when clamped to the spindle or immovably connected with the face plate and segmental worm wheel quadrant, is parti. lly rotated first forwardly and then backwardly at'slow speed, during the advance of the cutter across its face, resulting in the formation of the helical, teeth in the manner described.

The worm wheel quadrant, as shown, preferably extends equally on each side of the normal 01 initial position, the purpose of which is to provide for operation in either direction, depending on the direction of projection of the helical teeth.

In Figs. 7, 8 and 9, I show diagrammatically the progress of the milling cutter 0 across the face of theblank a on the radial line '0, o. During such time, theblank is rotated in the direction of the arrow, Fig. 7, until the cutter has advanced to the mid dle of the blank face, Fig.8, when the blank is reversed for the remainder of the cut in the direction of the arrow, Fig. 9, finishing the cut. This change of movement is effected by shifting the clutch '55 from gear 53 to gear or, or vice versa, because for a given direction or rotation of shaft 59 and feed of the cutter c, the blank will rotate in one direction when clutch 55' engages gear 53,

' and in the opposite direction when it engages gear 54. It is also necessary, of course, that in cutting the successive'teeth that these points of reversal of the helix or apices of the teeth be always in exactly the same line concentrically around the gear blank.

To this end, means are provided within the gear box Z) as follows: On shaft 59 are secured two narrow faced pinions 104, and which mesh respectively with gears 106 and 107. Each gear 106 and 107 is fixedly connected with sleeves or hubs 108 and 109 mounted toturn on a fixed shaft 110 extending across within the gear box; jacent ends of sleeves 108 and 109 have onlarged confronting disks or. flanges 111 and 112, each of which is provided with a peripheral notch or recess 113 and 11 i respectively. The ratios of gears 10 1-106 and 105107 are such that the notches 113114 will come into alineinent, or into registering position with each other, only at certain times, say for example, at every twenty-fourth revolution of gear 106 and flange 111.

The clutch 55 is designed to be shifted, either manually or automatically, by a controlled lever 115 pivoted at 116 within the gear. box 6 having a fork or shifting abutments 117 engaging the clutch and an extension 118 in working connection with an operating lever 119, extending upwardly through the top of the gearbox.

Extending downwardly from the other end of lever 115 is a pin, roller, orabutment 120 of a diameter to interfit and slip through the notches 113-414 whenthey are in reg The ad 7 ister, and which, of course, will prevent the lateral operation of the lever except at such times. By this means, clutch 55 can only be shifted from gear 53 to gear 54:, or vice versa, at such registering positions of the disks, one of which times occurs when the cutter c is midway of the face of the gear blank, as in Fig. 8. I

This is because the notches come into register once only in say every twenty-four revolutions of gear 106, or at such other predetermined time, depending on the gear reduction used in the machine, so that reversal of the gear blank is correspondingly effected and. controlled.

Therefore, with the machine set so that the clutch 55 can beshifted only when the cutter c is in the center of the face of the gear'blank, it will be impossible to shift the clutch during any inteunediate the cutter, or otherwise than at definite periodical positions of reversal, as say two, four, six, etc. inches beyond the midway position, since the assumed twentyfour revolutions of gear 106 and flange 111 corresponds to about two inches of the cutter. Such positions are well within the observation of the operator and no'miscake could be made as to the midway position.

It will be understood, of course, that in i the case of a Z-shaped or double involute Vii-shaped tooth, the rotation of the blank "may be interrupted or reversed two or more times during the transverse travel of the rotating cutter, by the use of suitable gearing adaptedto bring the notches 113-11-l into register at such times, in the same niannor as above described.

Shaft 59 is connected to shaft 00 by coupling 121 and is mounted in bearings transversely across a second gear box ob. Freely rotatable on shaft 60 isa sleeve or bushing 122'having a clutch terminal 122-, and a gear 12%, keyed to the sleeve, is in mesh with driving pin-ion of shaft 120. Shaft126 is driven through gear 127 by pinion 128 keyedto shaft 129, which extends across into gear box 7)?) from a third gear box 655. The extended end of shaft 60 carries a double throw clutch 130 splined on the shaft and operable by lever 130 to engage clutch terminal 123 of gear 124 or a similar clutch 31 of motor shaft Shaft 129 is driven through splined clutch 133 through either of, gears 134: or 135 mounted freely on the shaft, and each having a cosacti'ng clutch 136 and 137.

Motor shaft132 has a splined clutch 1'38, and, at each side thereof, freely rotatable pinions and 140 each having a co-acting 1 clutch 1 1 and 142 respectively. Pin ion 130,

when in clutch, drivesgeur 135 through idler gear 14-3 on shaft 1%, and pinion 14:0, when in clutch, drives gear 13st through reduction idler gears 145-440, fixed together, but free position of lit) to rotate on shaft l ll. Clutches 133 and 138 are operated by levers 147 and 1 18 respectively attending); inwardly through the casing of gear box 05?). i

ly this arrangement of gearing and clutches, I am enabled to utilize the power of widely variable speed motor (61) whereby to transmit power to shafts 37 and 59 at approximately the desired speed, with rcgulation of the number of revolutions con trolled by the change speed gearing provided.

For example, if the ratio ofgear train 12-l9=1 l3-135 is 1:1, and ratio of gear train l ttl lsm llfiltlsl is 1:4 and we hate a variable speed motor ()1 of 4: 1 range, we have in combination a total selective speed range of 16 z 1 under control ofthe operator, according to the speed of thefeed required for the end milling cutter c. It will notedthat the gearing of gear box Z1?) provides for a constant ratio gear reduction. The result, in elfect, is that with the variable gear trains in gear box blib'and the constant reduction train 'of gear box 57) (the latter by engaging clutch 130 with clutch 122-} of gear 12%) either may be user. during the working feed stroke of cutter c.

It will also be evident that by disengaging clutches 133 and 138 and engaging clutch 1 31) with clutch 1.31, shaft 60 will be driven directly by the motor. Such condition is utilized for the quick reverse action of the cutter a ready to begin the cutting of the next tooth. Return motion, of course, is eflected by reversing the rotation of the motor.

The described operation of cutting the individual teeth on the gear blank is on the assumption that the gear blank is fixedly "clamped to the face plate and through the face plate to the worm wheel quadrant 11. it the termination of each cutting operation, it is necessary, of course, to shift the blank around one pitch space to bring it into position for the next cut. I have provided indexing mechanism for such purpose, ada 'ited to provide for successive cutting of the entire annular series of properly spaced teeth around the blank.

To this end, the clamping bolt 18 first released by operation of the fluid actuated rack bar aiid nut segment 23, and the spindle i is then rotated to carry the blank around the desired distanc by the following inc-ans.

Index wheel 12, being fixedly keyed to the outer end of spindle 1, is provided with annular worni teeth engaged by. a worm 1 1?) which is adapted to be turned to the proper degree by means of gears connecting its shaft with the indexing mechanism 150. The latter is ,of well known construction, and need not'be described 'a detail, except to say the" l nel est e use O th usualchange speed gears between a driving pulley 151 and the worm 149, as will be readily understood. v

Pulley 151 is driven by belt 152 from pulley'153 of shaft lo hwhich in turn is geared with a motor 155 through pulley 156, belt 15?, pulley 15-8, and gearing" 159.

The motor and its gearing and shaft 154 are mounted upwardly above the sleeve 9 upon a bracket 160 secured to the rear end of the sleeve, while worm 149 and the indexing mechanism 150 are supported by a siinilar bracket 161, depending from the rear end of the sleeve, as in Fig. 6. These brackets and their supported parts normally occupy avertical position at approximately right angles to the horizontal plane through the spindle axis, but for convenience of illustration are shown broken away from the spindle, and in their proper vertical position in the plan view in which they are present.

These parts, being thus connected with the sleeve, will rock back and forth with it the sleeve, quadrant, and gear blank are rocked back and forth by the worm 30 throughout each cutting operation. Also, when worm 30 is inactive, thequadrant and indexing mechanism supporting brackets are immovable. If the face plate 8 is used and theclanipingbolt 18 is in release, the operation of motor 155 will drive the index mechanism and turn worm wheel 12 and the spindle 1 and arbor 3, or the arbor and face plate 8, so that rotation of the blank independent of the relatively fixed quadrant 11 results.

By means of the stop latch disks 112 and suitable change speed gears of the index mechanism 150, the periodical amount-of ro tation of the blank is determined to properly index or divide it into the desired nu1nber of teeth.

The construction of my improved machine ting helical teeth is as follows.

Assuming the gear blank has been mounted and chucked in proper position and the machine has been adjusted properly, involving correct location of the bearing support 7 with relation to the center 01, proper angular setting of the bed 73 for the cutter mechanism 0, selection of proper indexing change gears and. of the change gears for gears 13 and 46, the selection and afiixing of a suitable cutter 0, and that the several other necessary adjustments have been made, as described v First withdraw the cutter o by hand Wheel 72 to clear the face of the gear blank. Then make a trial run of motor 6]. until the cutter is approximately at the center of the face of the gear blank and the notches lit lls of disks lll llft a e in register,

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so that clutch may be engaged with either of the clutch gears 53 or 5%, stopping the motor at such position. Then, by means of hand wheel 88 and worm gearing 858'l, adjust position of table 69 and the end milling cutter c to theexact position midway of the gear blank face, which corresponds to the ot'f the cutting operation.

Clutches and i363 being in neutral position, throw clutch 130' into engagement \vi-th clutch 131 and by running motor 61 in reverse direction from that required for the forward stroke of the feed of table 69, return the cutter to a position clear of the back edge of the gear blank face. Then, by hand wheel 72 and screw '70, feed the cutter spindle towards the blank to proper cutting depth position, and engage clutches 133 and 138 with the desired selective. gear train of gear box bblnfand engage clutch 130 with clutch face of sleeve gear 12%. Start motor 61 at desired speed and also in rotational direction to give forward feed of cutter, and also start milling head motor 67 at proper speed to rotate the cutter 0. The cutter will then enter the edge of the blank face and cut the tooth groove, thedepth and width of cut gradually decreasing from the outside towards the center, due to the path of the cutter being on the radial line c, o,and theofi'ietting therefrom of the cone center 75 of the gear blank. p

\Vhen the cutter has reached the helical reversal point as described, the notches 113114 will be in register, and motor til should now be slowed down and, if necessary, stopped at this stage of the operation. Then, sh ft clutch into clutch of gear 5%, speed up or start the motor again, and continue the cutting of the remainder of the helical tooth groove in the opposed direction.

When the cutter has finished the cut, stop motor (ll, withdraw the cutter to clear the face of the blank, and with the motor driving direct for quick return, as described, withdraw and return the cutter mechanism to initial position at the outer edge of gear blank, ready for the next cut. The blank is then adjusted laterally one pitch space by the index mechanism to the next position, and the'cutting operation is repeated and these operations are continued unt l all the teeth are cut. i

If the teeth are not finished by the initial cut, and are merely rough cut, "a finishing end milling cutter may then be substfut d and the teeth cut to'finish'ed size by repeat ing the series of cutting operations, as described.

The treatment of the blank in this respect is largely within the province and judgment of the operator, dependent on the size and other characteristics of the gear being cut. If it is necessary to cut one side only of each tooth at a time, the entire series of side cuts for one s'de of each tooth may be made around the face of the blank, and then the series of opposite side cuts, by using the machine in the manner described, and with proper adjustment of the indexing mechanism, as will be readily understood by those skilled in the art. i

The mach ne as a whole provides for the cutting of helical teeth of bevel gears within a wide range as to size, number and shape of teeth, and other characteristics. It may be changed or varied in different details of construction or otherwise by the skilled mechanic within the scope of the following claims.

\Vhat I claim i '2 .1. A machine for cutting helical bevel gears having a rotatable blank support, 'means for alternately rotating the blank thereon forward and back, a rotating end milling cutter, a slidable support therefor driving mechanism for the cutter on said support, a. pivotally mounted laterally swinging table for the cutter support, and gearing for moving the cutter support thereon in a straight line movement during reversal of the blank I I 2. A machine for cutting helical bevel gears having a rotatable blank support, means for alternately rotating the blank thereon forward and back, a rotating end milling cutter, a slidable support therefor, driving mechanism for the cutter on said support, a pivotaliy mounted laterally swinging table for the cutter support, gearing for moving the cutter support thereon in a straight line movement during reversal of the blank, and means for supporting the table and fixedly locating it in position.

3. In combination with an intermittently and oppositely rotatable gear blank support and actuating and indexing mechanism therefor, a laterally swinging pivoted table, means for adjusting and securing it in position, a longitudinally slidable cutter support thereon, a feeding screw engaging :1 nut on the cutter support, actuating gean ing for the feeding screw, a rotatable end milling cutter on the support adapted to traverse the face of a gear blank in straight line movement during reversal thereof, and means on the cutter support for driving the cutter.

4. In combination with an .iu:ermittently ai'id'oppositely otatable gear b anksupport and actuating and indexing mechanism therefor, a laterally swinging pivoted table,

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means for adjusting and securing it in position, a longitudinally slidable cutter support thereon, a feeding screw engaging a nut on th cutter support, actuating gearing for the feeding screw, a rotatable end mill-- ing cutter on the support adapted to traverse the face of a gear blank in a stra ght line movement during reversal thereof, means on the cutter support for driving the cutter, and means for adjusting the cutter.

5. Cutter supporting and driving niechanism for a gear cutting machine as described consisting of a laterally swinging pivoted support, n'icans provid up, a carrying trackway therefor, a' table slidably mounted on said support having a nut, a breaded shaft engaging said nut, mechanism for transmittingdriving power to the threaded shaft through the pivoting center of the laterally swinging support, and a: longitudinally adjustable end in lling cutter and driving means therefor mounted on the table.

6. Cutter SUPPOltlHg and driving mecha nism for a gear cutting machine as described consisting of a laterally swinging pivoted support, means providing a carrying trackway therefor, a table slidably mounted on said support having a worm nut and bearings therefor, means for turning said nut and for locking it in position, a threaded shalt engaging the nut, gearing for actuating the threaded shaft at varying positions of the swinging support, and a longitudinally adjustable end milling cutter and driving means therefor mounted on the table T. The combination with the threaded shaft and slidable cutter table having a worm nut engaging the shaft between bearings on the table, of a nut-engaging worm and its spindle mounted on the table and provided with a hand wheel.

8. A. gear cutting machine having a slidable cutter table, a cutter housing provided with a rotatable end i'nilling cutter and a splined spindle therefor, a motor, gearingin splined engagement with the cutter spindle for driving, it from the motor, and means for adjusting the cutter housing and spindle on the table.

9. A gear cutting machine having a sliduble cutter table, a cutter housing provided with a rotatable end milling cutter and a splined spindle therefor, a motor, gearing" in splined engagement with the cutter spindle for driving it from the motor, and an :uljusting screw engaging a threaded poi. tion of the cutter housing for adjusting it on the table.

10. Means for supporting and adjusting a gear blank with relation to a tooth cutter consisting of a blank supporting spindle, a rotatable sleeve therefor, means embodying a releasable clamping bolt for flexibly connecting the blank'with the sleeve'and for releasing it therefrom, and means for partially rotating the sleeve and blank.

11. Means for supporting and adjusting a gear blank with relation to a tooth cutter consisting of a blank supporting spindle, a rotatable sleeve therefor, means embodying a releasable clamping bolt for flexibly connecting the blank with the sleeve and for releasing it therefrom, and means for partially rotating the sleeve and blank in alter nating opposite directions 12. Means for supporting and adjusting a gear blank with relation to a tooth cutter consisting of a blank supporting spindle, a rotatable sleeve therefor, means for flexibly connecting the blank with the sleeve and for releasing it therefrom, and segment and worm gearing connected with the sleeve for partially rotating the sleeve and blank 13. Means for supporting and adjusting a gear blank with relation to a tooth cutter consisting of a blank supporting spindle, a rotatable sleeve therefor, a worm segment connected with the sleeve, a driving worm therefor, and releasable clamping mechanism carried by the segment for fixedly connecting it with the gear blank:

ll. ii leans for supporting and adjusting a gear blank with relation to a tooth cutter consisting of a blank supportingspindle, a rotatable sleeve therefor, a face plate tixedly connected with the spindle having an annular clamping slot, an adjusting segment connected with the sleeve, a clan'iping' bolt ongaging the slot, and actuating mechanism therefor carried by the segment.

15. Means for sijipporting and adjusting a gear blank with relation to a tooth cutter consisting of a blank supporting spindle, a rotatable sleeve therefor, a face plate fixedly connected with the spindle having an annular clamping slot, an adjustable segment connected with the sleeve, a clamping bolt engaging the slot, a nut therefor having a toothed segment, and a fluid actuated rack bar carried by the segment engaging the nut.

16. The combination withthe spindle actuating face plate having an annular clainping slot and the sleevcactiiating segment and a bracket thereon; of a clan'iping bolt engaging the slot by its head and extending through the bracket by a threaded tcrinii'ial, a nut engaging the bolt and having a segmental toothed arm, a. rack bar engaging the arm and provided with a, piston, and a l flinch: ualiug i'zylinder tl'icrelor mounted on. the bracket.

17. The combination with the spindle actuating face plate having an annular clamp-- ing slot andthe slcevenctirating segment and av bracket theron; of a clamping bolt enthe slot by its head and xtending through the bracket by a threaded terminal,- a bushing therefor, a nut engaging the bolt and having a segmental toothed arm, ad-

ill)

justing set screws in the nut, and a fluid actuated cylinder, piston and rack bar mounted on the bracket and in operative engagement with the toothed arm.

18. Means for supporting and adjusting a gear blank with relation to a tooth cutter consisting of a blank supporting spindle, a rotatable sleeve therefor, means for fixedly connecting the blank with the sleeve and for releasing it therefrom, index mechanism for independently rotating the spindle and blank, and means for partially rotating the sleeve and blank.

19. In combination, a. blank supporting spindle, a rotatable sleeve therefor, means for fixedly connecting the blank with the sleeve and for releasing it therefrom, means for partially rotating the sleeve and blank, means for independently rotating the spindle carried by' the sleeve, and a longitudinally movable support for the sleeve.

20. In combination, a blank supporting spindle, a rotatable sleeve therefor, means for fixedly connecting the blank with the sleeve and for releasing it therefrom, means for partially rotating the sleeve and blank, means for independel'itly rotating the spindle carried by the sleeve, and a longitudinally movable support for the sleeve having a shaft geared with the sleeve rotating means and in sliding splined connection with a driving gear. I i

21. In combination, a blank supporting spindle, a rotatable sleeve therefor, means for fixedly connecting the blank with the sleeve and for releasing it therefrom, means for partially rotating the sleeve and blank, means for independently rotating the spin dle carried by the sleeve, a longitudinally movable support for the sleeve provided with sleeve bearings, a supporting base therefor, and means for securing the sleeve support to the base.

22. In combination with a rotatable blank reciprocating sleeve and a blank supporting spindle rotatably mounted therein and provided with an index wheel; supporting frau'iework fixedly connected with the sleeve and means for actuating the index wheel mounted thereon.

a 23. In combination with a rotatable blank reciprocating sleeve and a blank supporting spindle rotatably mounted therein and provided'with an index wheel; a bracket depending from the sleeve provided with gear,

ing engaging the index wheel, and a bracket extending upwardly from the-sleeve having a motor in driving connection with said gearing.

2st. The combination with a blank supporting spindle, a rotatable blank recipro eating sleeve, means for fixedly connecting and releasing the spindlev and sleeve and a blank carried by the spindle and gearing for rotata ly actuating the sleeve;- of an 111- dex wheel secured to the spindle and actuating gearing and driving mechanism therefor carried by the sleeve, whereby to impart independent rotatable movement to the spindle and blank.

25. In a machine for cutting helical teeth of bevel gears, means for reciprocably ro= tating the blank supporting mechanism and reversing the same at a predetermined point consisting of a main drive shaft, gearing for transmitting motion therefrom in opposing directions to the blank supporting mechanism embodying a direct driving and a reverse driving clutch, a shifting clutch therefor having a lever, and means controlled by the driving shaft for locking and unlocking the lever to ensure shifting thereof at a predetermined time.

26. In a machine for cutting helical teeth of bevel gears, means for reciprocably rotating the blank supporting mechanism and reversing the same at a predetermined point consisting 'of a reversing drive shaft, a power shaft, independent trains of gears between the reversing shaft and thepower shaft, each having a clutch, a co-acting clutch provided with an operating lever having a limiting abutment, and means in driving engagement with the power shaft providing clearance for said abutment at a predetermined time.

27. In a machine for cutting helical teeth of bevel gears, means for reciprocably rotating the blank supporting mechanism and reversing the same at a predetermined point consisting of a reversing drive shaft, a power shaft, independent trains of gears between the reversing shaft and the power shaft each having a clutch, change speed gearing interposed between said gears and the reversing drive shaft, a shifting clutch adapted to engage either of said trains of gears for direct and reverse drive respec tively, a shifting lever therefor having an abutment, and a pair of notched disks in variable operative connection with the power shaft adapted to come into registering position at a predetern'iined time to provide clearance for the lever abutment and to permit shifting thereof.

28. Shift controlling mechanisn'i for the clutch lever of a gear cutting machine consisting of a pair of confronting disks each having an annular recess, a clutch lever having an abutment adapted to pass through said recesses when they are in register but to engage the face of either disk when in nonregistering position, and a shifting clutch actuated thereby.

In combination with the reversing drive shaft of blank reciprocating mechanism of a gear cutting machine, and a clutchcontrolled power driven shaft and a time controlled shifting lever therefor; change speed gearing interposed. between the clutch controlled shaft and the "reversing drive shaft, substantially as set forth.

80. Power transmission mechanism for a 1 connecting it with the cutter mechauism clutch-controlled gearing connecting the line shaft with the blank reciprocating mechanism, a driving motor, and clutch controlled gearing for transmitting power therefrom tothe line'shaft.

31. Power transmission mechanism for a gear cutting mach'ne of the class described adapted to act ate blank reciprocating mechanism and :utter mechanism respectively consisting of a line. shaft and gearing connecting it withthe cutter mechanism, clutch-controlled gearing connecting the line shaft with the blank reciprocating mechanism, a driving motor, a shifting clutch for direct connection between the line shaft and motor, a gear box and gearing interposed between said shifting clutch and the line shaft, a gear box and clutch-contr0lled gearing interposed between the shifting clutch and the motor and a shaft connecting the gearing of one gear box with that of the other whereby to provide for variable speed drive of the line shaft.

In testimony whereof I hereunto aflix my signature.

HOWARD H. TALBOT. 

